So I messed up - I thought they were going to merge accounts this year. So I'm plat on CO, silver on UA. I'm flying UA IAD-CDG-IAD. Would like to upgrade return using my UA miles, since it's cheaper than a *A. But would like to credit CO for my plat bonus. Upgrade isn't available, so I'm waitlisted. If I switch to OP# at outbound checkin, will I lose my place on waitlist? Or if it clears, will they try do it as a *A from my OP account?